I think I am going to replace the bank 1, sensor 2 O2 sensor. I am getting code P0137. Any tips on how to remove this sensor? I know they can be stubborn at times. Also, is it a somewhat easy location? I have not crawled under my WK yet because my back is still stiff. What would be the best socket/tool to use? Thanks again, folks! I appreciate your input!!

make sure to soak it in a penetrating lube. Some are very difficult, I cannot say for sure on the 3.7 WK but I use an O2 sensor socket like this:

The problem is, occaionally it is too tight to get a ratchet on, in this case I try either a 7/8ths wrench OR I use the above pictured socket and hit the end (on the side) with my air hammer and a flat bit... Some come right out, some really don't.